It is possible to let a DHCP server update a DNS server as leases are accepted. /etc/dhcpd3/dhcpd.conf permits the association of MAC addresses with a host name and a fixed IP address. In this case, it’d be helpful if the DHCP server can update a designated DNS (usually the same one for use for DHCP client hosts).
With this feature, it is no longer as necessary for servers to have fixed IP addresses, as clients can use the host name instead of the IP address for addressing.